A standard wall-mounted mixing faucet assembly is provided with a faucet formed with hot- and cold-water inlets and a mixed-water outlet, a valve for connecting the inlets to the outlet, and an actuating member for the valve. This faucet is carried on a wall-mounted fitting that is secured in the wall and that is formed with hot- and cold-water couplings as well as hot- and cold-water outlet ports. The couplings are behind the wall surface to which the fitting is secured and are connected to the incoming water lines. The ports are exposed at the wall and mate with the inlets of the faucet, and means is provided for securing the faucet on the fitting with the inlets over the ports.
Normally the wall-mounted fitting is mounted in place for when the pluming hookup is roughed in. Then the wall panel, typically moisture-resistant gypsum board, is fitted around the adapter fitting and the wall covering, for instance tile, is applied to the wall panel. Only then is the faucet secured to this fitting.
Provision must be made to accommodate different wall thicknesses between the wall-mounted fitting and the faucet. For instance a common wall in a multiple dwelling may have two layers of 5/8" gypsum board plus 1/2" of ceramic tile for a total thickness of 13/4" while cheaper construction could have a single layer of 3/8" gypsum board covered with a membrane wall covering of insignificant thickness for a total thickness of about 3/8". Since the plumber doing the rough-in often has no clue about the final wall treatment, the adapter fitting must be able to accommodate a relatively wide range of wall thicknesses while still ensuring that the faucet will sit snugly on the wall and the connections to the faucet will not leak.
Thus as described in U.S. Pat. Nos. 3,880,183 and 4,846,207 various spacers are used as part of the adapter fitting. All of the spacers are employed for the thickest possible wall and none for the thinnest. Such an arrangement requires that the installer keep track of these various parts prior to installation and, unless they are saved, any subsequent change in wall covering will normally require a new kit to be obtained. Furthermore the adapter length is set in steps so that obtaining a snug fit of the faucet to the wall is unlikely unless by chance the wall thickness corresponds exactly to one of the settings for the adapter.